Headlights wont turn off

I just bought this truck a week ago and so far everything has been great then all of a sudden my headlights and radio wont turn off even though the headlight switch isn't on.

the dome light doesn't stay on, just the headlights and radio.

everytime I turn my truck off I have to disconnect the battery so that it doesn't die.

why is this happening and how do I fix it?

 

It could be the ignition switch
I doubt it's a fuse, but check them anyway.
http://youtu.be/ksrsXwwukFc

 

Did the truck have an alarm or remote start that you know of? Maybe look around under the dash for any wiring that looks botched. Good luck!

 

Are the headlights and radio tied into the same circuit? I doubt they are but I have to ask. It does sound like an ignition switch but it could also be a bad headlight switch as well if they are both tied into the same circuit indeed.

 

Start by checking all your fuses. It sounds like the lights and radio are getting constant power somehow.

 

Here is a thread on CT where some one had a similar problem. Turned out to be a bad headlight relay.

http://www.customtacos.com/forum/showthread.php?t=108565

 

Looks like im going to have to take it to a shop..

 

Shit. I was thinking the relay too. They DO stick sometimes.

OP here is an easy thing to do. Just pop your hood pull your fuse cover and identity the headlight relay. Pull that one from it's home and then pull a similar relay by it (wiper relay or something accessory related that is non important at the moment) and put that relay in where the headlight relay originally was. If your lights now turn off upon removing the key then you know that one is the problem. You can easily find those relays at many auto parts stores if not the dealer for sure for a couple bucks.

 

I took it to a shop and they said its because my windshield was leaking (it has a huge crack in it) and a lot of water leaked into the fuse box and corroded it so they completely took it apart and cleaned it and then covered it up. looks like I need to replace my windshield sooner than I wanted to. this is what happens when you live in Vancouver, BC, Canada.. way too much rain